Door stop



FIG. 1 is a front elevation view of a door stop showing my new design;

FIG. 2 is a rear elevation view;

FIG. 3 is a side elevation view;

FIG. 4 is a top plan view; and,

FIG. 5 is a bottom plan view of a door stop showing my new design. 

The ornamental design for a door stop, as shown and described. 